Update warehouses.md

docs/cloud/features/05_infrastructure/warehouses.md

@@ -112,7 +112,7 @@
   - Can export data externally
 - **read-only**
   - Can only read data; it cannot write or modify data in ClickHouse
-  - Does not perform background merge operations, so its resources are fully dedicated to read queries
+  - Does not perform background merge operations outside of system tables, so its resources are fully dedicated to read queries
   - Can still export data externally (e.g., via table functions), but cannot change data inside ClickHouse
   - Idles without delay, unlike read-write services which may be kept awake by background merges.
 
@@ -184,7 +184,8 @@
 If you manually stop a service, you will need to start it up again in order for queries to be executed. 
 
 - **There is currently a soft limit of 5 services per warehouse.** Contact the support team if you need more than 5 services in a single warehouse.
-- **Primary services cannot have only one replica** While secondary services can have one replica, the primary service must have at least 2. 
+- **One replia Primary Sservice** Today, the default behavior is the secondary services can have one replica, the primary service must have at least 2.
+  To enable single replica primary services, please contact support. This behavior will be enabled by default in Q2 2026.
 - **Primary service idling** Today, the default behavior is that the primary service cannot auto-idling. It is disabled once the secondary service is created. To enable this, contact support to enable parent service idling. Parent service auto-idling will be enabled by default in Q2 2026 (existing services will have access to the feature, new services will have it enabled by default). 
 
 ## Pricing {#pricing}